This article is part of a 10-part series where we discuss interesting APIs that were added to our directory during 2016. Business and Productivity APIs are covered in this segment. The APIs were chosen by our researchers, by popularity according to website traffic, and by mentions on social media.

Rebelmail publicly launched its interactive email API. After successful private integrations with ESPs like Mailjet, SendGrid, and others; Rebelmail is ready for third party integrations across the board. Through the API, users can build, send, and track interactive emails directly within an app.

We've added twenty six APIs to the ProgrammableWeb directory in categories including Messaging, Transportation, Location, and Open Data. Highlights today include an API that can provide developers with Uber driver information, and the Hypertrack.io API, for adding location tracking features to apps.

To provide more options in searching for relevant contacts, Microsoft has decided to transition WorkingWith API users to its new People API. The People API not only provides more robust metadata than the WorkingWith API, the People API includes greater browse/search functionality and ranking system.

Google Contacts API gives client applications access to a user’s contacts list where the application can create new contacts, update or delete existing ones, or query for contacts that match particular criteria. This tutorial explains how to implement the API in C# and ASP.NET with OAuth 2.0.

Twenty One APIs have been added to the ProgrammableWeb directory in categories such as Transportation, Email, and Financial. Featured today are some smart city APIs: One for finding clean water in Flint, Michigan, and three more for use with the City of Chicago's bike sharing program.

Google has released an updated Gmail API that functionally replaces the Email Settings API. The Gmail API includes a number of new endpoints that enable features previously unavailable through any Google API. Developers have access to filters, auto-replies, send-as aliases, and more.

SendGrid announced its latest endpoint for its Web API: v3/mail/send. The endpoint rounds out the v3 release that began last year. With the new send endpoint, SendGrid has realized its goal of complete API management via API. All of the v2 functionality remains available with additional features.

SendGrid announced they are sunsetting two of their API endpoints this month. In an email sent to their API consumers, Sendgrid stated that all API calls must now use a new base URL. They also directed developers to reference SendGrid’s API documentation or contact them through their attached email.

Do you know if your emails reach your users' inbox? You may see clicks and opens, but were all your emails seen? SparkPost offers this certainty to developers for free or low cost. SparkPost sends 25% of the world's legitimate emails. They make solving email delivery as easy as making an API call.

Nine APIs have been added to the ProgrammableWeb directory in categories such as Recognition, Software-as-a-Service, Fonts, and Travel. Included today is an API for Webconverger, for Web kiosk accessibility. Here, we summarize the new additions and how they can assist developers.